This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Several lines of evidence suggest that disturbances of 5-HT and DA pathways contribute to core eating disorder pathophysiology. This pilot study seeks to determine the most effective dose and side effect profile and safety/tolerability. If these objectives are met, a larger double-blind, placebo-controlled trial may be necessary to demonstrate the primary and secondary objectives as well as to determine whether response is specific to AN subtype. This study may be adequately powered to detect a difference in core eating disorder symptoms. Primary Outcomes: Primarily we will seek to show that Quetiapine is superior to placebo in terms of reducing core eating disorder symptoms on the Yale-Brown-Cornell Eating Disorder Scale (YBC-EDS) and the Eating Disorders Inventory-2. Secondary Outcomes: We will seek to show that Quetiapine is superior to placebo in reducing anxiety (STAI), depression (Hamilton DI), obsessionality (YBOCS), or weight gain (BMI) in patients with DSM-IV AN (either restricting or binge-eating purging types) when administered for 8 weeks. Additionally, we will seek to show that Quetiapine is superior to placebo at reducing positive and negative symptoms on the Positive and Negative Symptom Scale (PANSS). Finally, we will track Quetiapine response, course and outcome using both the Pittsburgh Quetiapine Medication Management Assessment and interview.